Internal-combustion engine



- l I05 24 i D. V. BOUREAU.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JAN. 26, I918.

Patented Nov. 9; 1920.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED mnzs, 19 8.

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I D. V. BOUBEAU. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JAN-26, 191s.

Patented Nov. 9, 1920.

3 SHEETS--SHEET 3- 57 WmZOI M K 6mm .UNITED surge earner orricng DESIRE V. BOUREAU, 0F DETROIT, MICHIGAN.

INTERNAL-CQMBUSTION ENGINE.

Application filed January 26, 1918.

To afZ ac/rem it may concern Be it known that I, Dnsrni': V. Bonnnnn,

a citizen of France, who have declared my intention of becoming a citizen of the United States, residing at Detroit, county of Wayne, and State of Michigan, have invented certain new and useful Improvements in Internal-Combustion Engines, of which I declare the following to be a full, clear, and exact description.

This invention relates to improvements in internal combustion engines and more particularly to engines of the two-stroke cycle type.

The principal object of my invention is to provide an engine of this type having improved means for scavenging the exhaust gases and subjecting the charge to a pre liminary compression.

A. further object is to provide an improved piston construction of light weight and easily cooled.

A further object of my invention is to provide an engine accomplishing the above objects and in which there is no side thrust on the piston.

A further object of my invention is to provide a very efficient, powerful and quiet engine of the two-stroke cycle type. I

Further objects, and objects relating to details of construction and economies of manufacture, will definitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and means described in the following specification. My invention is clearly defined and pointed out in the ap pended claims.

A structure comprising a preferred embodiment of my invention illustrated in the accompanying drawing, forming a part of this specificatioinin which Figure I is a view in side elevation of an engine embodying my invention, looking on the valve side of'the engine.

Fig. II is an enlarged, vertical, sectional view through the engine, taken on theline II-II of Fig. I, the manifolds and fuel conduits being omitted.

Fig. III is an enlarged, fragmentary, sectional view of the piston rod stuffing box, the view corresponding to a part of Fig. II.

Fig. IV is fragmentary, sectional view taken substantially on the line IVIV of Fig. II.

Fig. V is a fragmentary, sectional view Specification of Letters Patent.

Serial No. 213360;}.

taken substantially on the line V-V of Fig. II.

Fig. VI is a fragmentary, detail, sectional view taken substantially on the line VI-V I of Fig. XIII.

Fig. V II is a fragmentary, detail, sectiona-l view taken substantially on the line VlL-VII of Fig. II. I

Fig. VIII is a transverse, sectional view through the piston.

Fig. IX is an enlarged, detail, sectional view through a part of the piston head corresponding to part of Fig. II.

Fig. X is a plan view of the cap for closing the recess in the piston head.

F ig. XI is a vertical sectional vie. through the engine on the line IIII of Fig. I. i

Fig. XII is a similar view on the line XII-XII of Fig. I.

Fig. XIII is a similar view on the line XIII-XIII of Fig. I.

-Fig. XIII is a similar view on the line XI -XIV of Fig. I.

Fig. XV is a detail, sectional view on line XV-XV of Fig. I, and i XVI is a detail, sectional view of the cylinder head showing a modified'form of automatic scavenging valve.

In the drawings, similar reference numerals refer to similar parts throughout the several views, and the sectional views are taken looking in the direction of the little arrows at the ends of the section lines.

Considering the numbered parts of the drawing, I have shown an engine comprising a crank case 10 and a cylinder bloclcll having a base 12, the'crank case 10 and base 12 having cooperating flanges. 13 and let through which the bolts 15 pass to secure the base of the cylinder block to the crank case. In the cylinder block 11 there are formed plurality of cylinders 16, in this case I have shown four although my inventionis not to be restricted to a four-cylinder engine, each cyhnder being provided with a skirt 1? extending downwardly into the base 12 of the cylinder block. A. liner 18 is inserted in each cylinder 16, saidfliner having a radially extending flange 19 at its upper end which rests on the upper edge of the cylinder. The liner 18 carries a trans versely extending partition 20 dividing the cylindrical liner into an upper and lower part. may be cast from aluminum and ,the hners Patented Nov. 9, 1920. l

The cylinder block and crank case and pistons and other relatively moving parts made of steel and machined and then there being one of these valve chambers for each cylinder and each valve ch amber has its axis extending vertically parallel tothe axis of the corresponding cylinder. A liner is fitted within each valve chamber 24, each liner having a radially-extending flange 26 at its upper end resting on a corresponding seat, formed at the upper'end of the valve chamber, and held 1n place by the removable cap- 27 closing the upper end of the valve chambers.

The valve chambers 24 are all interconnected at their upper ends by the pipes or tubes 28. i

A cylinder head 29 is removably fastened on the upper end of the cylinder block 11 in any suitable manner, said head having the 'water spaces 30, communicating with the water spaces 22 of the cylinder block, and the water outlet manifold 31. The head29 carries at its lower surface the concave sur-, faces 32'which serve as heads for and close the individual cylinders 16. l

The partition 20 in the liner 18 has a central cup 33 having an axial opening therethrough. The vertical wall'of this cup is internally threaded at 34- and a flange 35 extends radially inwardly from this vertical wall. An inner cup 36 seats in the axial opening of the cup 33 having an outwardly extending flange which seats on the'fiange 35 and having an axial opening therethrough. A ring of soft bearing metal 38 rests in cup 36 and a ring of hard metal 39 seats on said ring, being retained in place by the retaining cup 41 which rests on another soft metal ring 40' disposed on top of the .ring 39. The cup 41 has an axial opening 42 therethrough in line with the opening 37 in the cup 36 and. an externally threaded part 43 screwing into the internally threaded part of the cup 33'. .The cup 41 has on its lower edge a beveled flange 44 which engages 'a similar'flange on the cup 36 to make a tight seat. V

A cross-head 45, which is cylindrical in cross-section, works in the lower part of the cylinder below the partition 20 and the pistonvrod 47 is integral with the cross head and extends upward and axially therefrom through the openings 37 and 42 vin the stufii'ng box and through the bearing rings 38, 39 and 40 into the cylinder 16. The upper end 48 of the piston rod 47 is tapered and eats in a corresponding tapered seat in the hub 50 of the piston which works in the cylinder 16. The piston is of skeleton formation so as to reduce its weight and facilitate cooling and'comprises an outer cylindrical wall 49 connected with and supported ton rod 47 to retain the hub 50 of the piston thereon. The head 54 of the piston is con cave and has an axial opening therein closed by a cap 55, externally threaded at 57, and screwed into the opening, said cap having a beveled flange 58 engaging a corresponding seat in the head 54. This arrangement per mits thecool air drawn into the lower part of the cylinder below the piston to circulate freely in contact with the inner surface of the piston head and wall so as to greatly facilitate the cooling of the piston. A plurality of sockets 59 are formed in cap 55 into which the teeth of a suitable tool may be introduced in removing the cap.

A concave recess 60 is formed in the lower part of cross-head 45 and the upper end of connecting rod 62 is pivotally mounted on the pin 61 carried by the cross-head. The lower end of the connecting rod 62 is connected with the arm 63 of the crank shaft 64 which is suitably journaled in the crank case. A gear. 65 is mounted on the crank The lower end of connecting rod70 is connected to arm 69 of the counter crank shaft 63. The upper end'of the connecting rod is pivotally connected to a pin 71 carried at the lower end of piston valve 7 2.

The exhaust port 73 is provided in the side wall of the cylinder 16, about midway between the upper end of the cylinder and the partition 20. A port 7 4 is formed in the outer side wall of each valve chamber 24 and each of these ports is in communication with one of the branches of anintake manifold 76 which connects with a carbureter 77. A second port 7 5 is also provided, in the side wall of each valve chamber 24, communicating with the open air through an air' shaft, at one end of the case, and meshes V controlthe intake of air for scavenging and cooling therpiston. A transverse port 78 is provided in the piston valve in such a position that it may ahne with either port 7 4 or 7 5 depending upon the position of the p1s-' ton valve. A port 79 connects the valve chamber 24 with cylinder 17 below the partition 20 and a similar port 80 connects the valve chamber with cylinder 16 above the partition 20, the ports 79 and 80 being in line with ports 7 4t and 75, respectively.

A port 81 is formed in the side wall of the valve chamber 24 near the upper end thereof and a cooperating port 83 connects the valve chamber 24 and cylinder 16, port 83 being so located that it is only uncovered by the piston during the lower half of the piston stroke. An inclined port 82 is formed'in the piston valve which port, at certain positions of the valve, connects the ports 81 and 83. A relief port 84 extends transversely of the piston valve 72, above the port 82, being so disposed that, when the piston uncovers port 83 on the power stroke, the port 84: is in line with the port 83 and with a recess 85 formed in the outer side wall of the valve chamber. A port 86 extends through the side wall of cylinder 17, just below the partition 20, and this port is connected with the port 81 feeding one of the other cylinders by means of a pipe or conduit 91. These pipes connecting the ports 86 and the ports 81 are so arranged that each cylinder feeds compressed gas to the cylinder which fires next in order after it. In the drawings, the crank shaft is such that the cylinders fire in the order A, B, D, C, andcylinder A feeds B, B feeds D, D feeds C, and C feeds A. If the firing order is different the arrangement of the pipes 91 will, of course, be different but, in any event, each cylinder feeds to the one next to fire.

Passages 92 are cored in the cylinder block each of which communicates at its lower end with a port 93 opening into one of the cylinders 16 just above the partition 20. Passages 9-1 are formed in the cylinder head which connect with the upper ends of passages 92 in the cylinder block. Each of these passages 94 opens into a transversely extending cylindrical passage 95 in the cylinder head, there being one of these passages extending above each of the cylinders. Each passage 95 has an enlarged portion or chamber 96 in which is seated a cylindrical slide valve 97 having a skirt 98 extending from the forward end thereofand having a beveled edge seated on a corresponding seat at the end of chamber 96. Each skirt has a plurality of ports 100 .therethrough and there is a groove 101 in the side wall of chamber 96 connected by port 90 with the engine cylinder. A compression spring 102 is seated behind the valve 97 and held in place by cap 103 closing the end of chamber 90 and having a vent 104; therethrough. A suitable spark plug, (not shown), is provided for the combustion chamber of each cylinder. I v

A wide groove 105 is cut in the side of piston valve 72, and an oil port 106 extends through the side of the valve chamber 21 at such a point that it communicates with groove 105 at all points of the piston valve stroke. The oil ports 107 are connected with the branches 106 of an oil manifold connected with a pressure lubricating system.

In Fig. XVI, I have shown a modified form of automatic scavenging valve in which the head 29 has passages 110 connecting with the passages 92 inthe cylinder block. chamber 111 is. formed over each cylinder andeach of the passages 110 connects with one of the chambers 111, said chambers be- .ing connected with the respective cylinders by ports 112. A supporting member 113 is provided in each cylinder 111 and the valve stem 11 1 of the valve 115, normally closing port 112, is slidably mounted in said member 113. A. spring 116 is compressed between member 113 and washer 117 carried by the upperend of the valve stem. Chamber 1.11 is closed by the removable cap 118.

From the description of the parts given above, the operation of this engine should be very readily understood. This engine is of the two-stroke cycle type in which an explosion .occurs at each complete stroke of the piston. Furthermore the charge ignited is given a preliminary compression before passing into the combustion chamber where it receives a final compression before explosion takes place. I have also provided means for scavenging the combustion chamher very effectively and for cooling the pis- 7 ton by directing cool air in contact with the walls thereof.

In Figs. XI, XII, XIII and XIV, I have shown the engine in four different positions of the crank shaft, ninety degrees apart. In Fig. XI the explosion has just octurred and the piston is starting on its down stroke. Air, which has previously been drawn into the cylinder below the. piston is compressed between the piston'and the partition 20 on the down stroke. The piston valve '72 moves down with the pi ton and brings port 78 in line with ports and 79 so that a fresh charge is sucked into cylinder 1'7 in which the cross head 15 is descending. During the entire down stroke of the piston gas is drawn into the pro-compression chamber in the cylinder 17 betweenpartition 20 and cross head 45. At the end of the down strokeof the piston the piston valve '72 is moving up and port '78 is just moving out of line with ports 74: and 79. As the piston moves up on its return stroke, the gas drawn into the precom pression chamber is compressed by the upwardly moving cross head 45 to give a pre liminary compression to the Ihe precornpressi'on chamber of each cylinder is connected to the combustion chamber of the cylinder next to fire by a pipe 91 through theports 81 and 83 and the inclined port 82 of the piston valve 72. As the piston starts on its up stroke, the piston valve is moving up and, at the instant that the upwardly moving piston closes, the exhaust port 73, the plston valve has moved so that port 82 is in line with ports 81 and 83 and a charge of gas, which has been compressed in the precompression chamber of the cylinder about to tire, rushes in, through these ports 81, .82 and 83, to the combustion chamber and is given a further compression by the piston as it moves upwardly to top dead center at: or. near which the explosionoccurs. 1

As the piston movesup on its up stroke,

airis drawn in, through ports 75, 78 and 80, to the pump chamber formed 1n the lower partof the cylinder 16 between the piston and the partition 20. hen the piston starts on its down stroke, the piston valve has moved down so that port '78 and ports 7 5 and 80 are out of line and consequently the air compressed in the pump chamber by-the descending piston is forced throughport 93 and passages 92 and 941' against the end of the valve 97. The pressure of spring 102 is regulated so that the air pressure does not counteract the'pressure of the spring until the beginning of. the lasthalf of the downstroke of the piston and then the air pres sure forces the valve 97 back and the compressed airenters the combustionchamber through passage 95, ports 100, groove'101 and passage 90. This cool air rushing down into the combustion chamber assists in driv ing the burned gases out through the exhaust port which s uncovered by the piston about this time and thus insures a thorough scavenging of the combustion chamber. Furthen more the cool air rushing in assists materiallyin cooling the cylinder and piston walls thus eliminating all danger of pre-ignition. The gas left in the combustion chamber which mingles with the fresh charge is fresh air admitted under pressure instead of burnt gases as in other types of two-cycle engines and hence a more efficientoperation is secured. V p

7 hen the piston starts up on its up-stroke the air'pressuredrops and the spring 102 returns the valve 97 so that it closes the port 90 which leads into the combustion chamber. A reliefport'8 1 is provided in the pis-' ton valve 7 2 which port is inline with port -83 and recess 85 when port 83'isunco vered by the piston on the down-stroke andcone sequently the sidethrust or pressure dueto the expanding gases is transmitted to the wall of the valve chamber and does not act on the piston valve. 7

V The piston is of skeleton formation and is, consequently very light. the air drawn into the pump chamber passes freely around the hub 50 of the piston in contact with the inside of the piston wall and head and hence the piston can be very readily kept cool, the heatgenerated by the xnlosion being to a certain'extent transmitted'to the air which is in the pump shaft 64 to drive the .latter.

Furthermore r chamber and in contact with the inner piston walls. Furthermore the mass of metal in the piston is not great and the retention of heat in the piston is consequently small. The cross head 45 really serves as'a supplemental piston and the piston rod a7 is an integral part of the cross head. The piston is compelled to move in straight rectilinear lines and all side thrust is taken up by the cross head 15 and. the piston rod 17 which vreciprocates in the stufiing box formed in the partition 20. Consequently there is no side slap of the piston. The cross head not only serves to take up the side thrust from the crank shaft but also acts as the piston working in the precompression chamber to give a preliminary compression to the charge. The combustion and pump chamhere are surrounded by a water jacket 21 so that they may be eficiently cooled and the cooling water enters the jacket from waterv manifolds, (not shown), above and below theexhaust port 73, so that the coolest water in the system/comes in contact with the parts where the heat is likely to be greatest. Y

The cross heads 45 are connected to the throws 63 of crank shaft 64: by connecting rods 62 and the force of the explosion is lution earlier than the top dead center of the piston stroke. The piston valves 7 2 each work in a cylindrical valve chamber 2 1 opening at its lower end into the crank case and closed at its upper endby cap 27. The upper ends ofthe valve chambers are connected by pipes 28 so that the air pressure in the upper ends of the valve chambers will equalize through these pipes. A groove 105 is cut in the side of the piston valve 72 and oil is admitted; through pipe 107 and port 106 so as to lubricate the piston valve.

In Fig. XVI, Lhave shown *amodified automatic valve which may be used in place of the valve 97 shown in the other views.

When the pressure in the pump chamber 7 exceeds the pressure of spring 116, valve 115 will open and a jet of scavenging air will enter the cylinder from passages 92, 110 and through port 112. The valve closes automatically when the pressure drops.

. In the description'above, I have referred to the combustion chamber, the pump chamher and the precompression chamber. By the combustion chamber, I mean that part of each cylinder limited above by the cylinder head and below by the piston head. By the pump chamber, I refer to that part of each cylinder between the. piston and the partition 20 and, by the. precompression chamber, I mean that part of each cylinder below the partition 20 and above the cross head 45.

In the form of my engine herein illustrated, the pump chamber is used to compress air for scavenging the combustion chamberand the charge is preliminarily compressed in the precompression chamber. This is the preferred form of my engine but, if desired, the port '7 5 might be connected with intake manifold 76 and both pump chamber and precoinpression chamber used to compress the charge which is fed to the combustion chamber. The connections might also be so arranged that the air for scavenging is compressed in the precompression chamber and the fresh charge compressed in the pump chamber. I contemplate both of these arrangements, as well as numerous others, which will occur to thoseskilled n the art, as within the spirit of my invention. I have illustrated a four cylinder engine but my invention is not limited to this as the principles here disclosed are not de pendent on the number of cylinders n the engine.

I am aware that the particular embodr ment of my invention, here shown and described, is susceptible of considerable var1 ation without departing from the spirit thereof and, therefore, I desire to claim my invention broadly, as well as specifically, as indicated by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In an engine of the class described, the combination of a plurality of cylinders, each provided with an exhaust port uncovered by the piston toward the end of the power stroke, and an intake port disposed in a planejust above the exhaust port; a piston working in each cylinder; a crankshaft driven by said pistons; means for preliminarily compressing a charge of gas; means for injecting a scavenging jet of a1r through the upper end of each cylinder toward the end of the power stroke; means for injecting a compressed charge through said intake port toward the beginning of the compression stroke; a piston valve driven by the crankshaft for controlling said intake port; and a pressure-operated valve for controlling the scavenging jet.

2. In an engine of the class described, the combination of a plurality of cylinders closed at both ends; a piston working in each cylinder and dividing it intoupper and lower chambers; a crank shaft driven by said pistons; an air intake port opening into said lower chamber; a gas intake port open} ing into said upper chamber; a single valve controlling said air and gas intake ports; a passageconnecting. said upper and, lower chambers; and a pressureoperated valve in said passage. is i 3. In an engine of the class described, the combination of a plurality of cylinders closed at both ends; a piston working in each cylinder and dividing it into upper and lower chambers; a crank shaft driven by said pistons; an air intake port opening into said lower chamber; a gas intake. port opening into said upper chamber; a single slide valve driven from said crank shaft and controlling both said ports; a passage connecting said upper and lower chambers; and apressure-operated valve in said passage. v

4. In an engine of the class described, the combination of a plurality of cylinders closed at both ends; a piston working in each cylinder and dividing it into upper and lower chambers; a crank shaft driven by said pistons; anair intake port opening into said lower chamber; a gas intake port opening into said upper chamber; a piston valve reciprocable'in a path parallel to the piston and driven by said crank shaft, said piston valve controlling both, said ports; a passage connecting said upper and lower chambers; and a pressure operated valve in said passage. V

In an engine of the class described, the combination of a plurality of cylinders, each cylinder including a combustion chamber, a pump chamber and a precompression chamber all in axial alinement; a piston for each cylinder having anupper head working in the combustion and pump chambers and a lower head working in the precompression chamber; a crank shaft driven by said pistons; an intake port for each of said pump chambers; an intake port for each of said combustion chambers; a passage connecting the pump chamber and .the combustion chamber; a pressure operated valve in said passage; valves controlling said intake ports; and passages connecting each precompression chamber with the intake port of the combustion chamber of the cylinder firing next succeeding.

6. In an engine of the class described, the combination of a plurality of'cylinders, each cylinder including axially alined combustion, pump and precompression chambers; a piston for each cylinder having an upper head working in two of said chambers and a lower head working in the third chamber; a crank shaft driven by said pistons; intake ports for each of said chambers; passages connecting .the pump and combustion chambers of each cylinder; pressure-operatedvalves in said passages; valves controlling said intake ports; and passages connecting the precompression chambers with thecombustion chambers 01"? the cylinders firing next succeeding.

, 7. In an engine 01 the class'described, the

combination ofa plurality of cylinders, each cylinder including axially alined combustion, pump and precompression chambers; a piston for each cylinder having an upper head working in two of said chambers and a lower head working in the third chamber; a crankshaft driven by said pistons; intake ports for each of said chambers; passages connectin the pump and combustion chambers of 'each'cylinder; pressure operate-d valves in said passages; a single slide-valve controlling at least two of the intake ports for each cylinder; and passages connecting each precompression' chamber with the intake port of the combustion chamber firing next succeeding.

8. In an engine of the class described, the

combination of a plurality of cylinders, each cylinder including axially alined combustion, pump and fprecompression chambers; a piston for each cylinder having an upper head working in two of said chambers and a lower headworking in the..third chamber;

crankshaft driven by said pistons; intake ports for each of said chambers; passages connecting the pump and combustion chambers of each cylinder; pressures-operated valves in'said passages; piston valves driven by the crankshaft and reciprocable in paths parallel to the pistons,eachpiston valve controlling at least two of the intake ports of the corresponding cylinder; and pass sages connectingeach precompression chamher with the intake port 01 the combustion chamber of thecylinderfiring next succeeding. 9. In, an internal combustion engine of the class described, the combination of a cylinder block having plurality of cylinders,

each cylinder including axially alined combustion, pump and precompression chainbers; a piston for each cylinder having an upper head working in two of said chambers and a lower head working in the third chamber; a crankshaft driven by said pis tons; intake ports for each of said chambers' passages cored in said cylinder block driven by said crankshaft and re'ciprocable 7 in. pathsparallel to thepistons, each pistonvalve controlling at least two of the intake ports of the corresponding cylinder; and passages "connecting each precompression chamber with the intake port of the combustion chamber of the cylinder firing next succeeding. r r

10. In an internal combustion engine, the combination oi a plurality of cylinders; partition wall dividing each cylinder into an upper and alower portion; pistons each having a headworking in the upper portion of the cylinder and a head working" in the lower portion thereof; a crankshaft driven by said pistons; an intake port for the lower portion oi each cylinder; a pair of intake ports for the upper portion of each cyl-in der; a single slide valve for each cylinder controlling said intake ports; passages connecting the top and bottom of the upper portion of each cylinder; pressure-operated valves in said passages; and passages connecting the lower portion of each cylinder with the upper intake port of the cylinder firing nextsucceeding,

11. in an internal combustion engine, the combination of a plurality oi cylinders; a partition wall dividing each cylinder intoan i per and a lower portion; a piston working in each of said lower portions; connecting rods slidably mounted said partition walls and carried by said pistons; upper pistons secured to the upper ends of said connecting rods and working in the upper portions of said cylinders; a crankshaft driven by said pistons; an intake port for the lower portion of each cylinder; apair of intake ports for the upper portionof each cylinder; a single slide valve for each cylin der controlling said intake ports; passages connecting the top and bottom otthe upper portion of each cylinder; pressure-operated valvesin said passages; and passages connecting thelower portion of each cylinder with the upper intake port of the cylinder firing next succeeding.

"In testimony whereof I affix my signature. 

